1. Field of the Invention
The present invention relates generally to the field of communications, including paging, cellular and personal communication services (PCS). In particular, the present invention relates to confirming receipt of a message by a messaging unit, such as a pager.
2. Related Art
A paging service is one type of communication service that is related to the present invention. It is a one-way wireless messaging system which allows accessibility to someone away from the wired communications network.
A basic paging system has several key components. The key components include an input source, a telephone network, such as the public switched telephone network (PSTN), one or more paging terminals, a radio frequency (RF) link system, and messaging units or pagers. The paging system is typically operated by a service provider, or carrier, who typically incurs the cost of building and operating the system. Authorized government bodies, such as the Federal Communications Commission (FCC), license bandwidth to the service provider to operate a paging frequency, or channel, within a regulated geographical area. The geographical area can be either local, regional or national in scope.
As mentioned above, another key component of a paging system is the input source. The input source can be a telephone, personal computer, desktop entry device or an operator dispatch where someone is paid to take and enter a message. The desktop entry device is typically leased or sold by the paging service provider.
A page is sent over the PSTN, another key component of the paging system. Alternatively, a page can be sent in other ways, such as over a private switched network, or directly from a computer to a computer network (such as the Internet). In the United States, Regional Bell Operating Companies are the PSTN providers who own and operate the PSTN. The PSTN provider typically owns a twisted pair of copper wires which connects the input source to a PSTN-owned switch.
The page typically consists of a message, the pager's unique number and any other information required by the paging system. The message consists of information the caller is trying to send to the person carrying the pager. The message typically is either a numeric message, representing a phone number the person receiving the page is to call, or a text message.
The next key component of a basic paging system is paging terminals. Paging terminals serve as an interface to the PSTN switch, or to a private switch if public access is not required. The PSTN views the paging terminal as just another switch. The paging terminal is responsible for receiving, processing, storing and forwarding information from the caller. Additionally, it encodes the page for transmission through the carrier paging system. Typically, an encoder accepts the incoming page, validates the pager number and encodes the pager number and message into the appropriate paging signaling protocol (e.g., FLEX.TM.).
The paging signaling protocol is the root of all paging systems. A protocol is a type of language, or set of rules, that allows information to flow over a telephone network through the airwaves and connect with a pager. These rules control the qualities both the service provider and the caller find important. Such qualities include capacity, latency and signaling speed, pager battery life and data integrity.
One example of a paging signaling protocol is the FLEX.TM. paging protocol. The FLEX.TM. paging protocol is a multi-speed, high-performance paging protocol adopted by leading service providers worldwide as a dc facto standard. Once data is received from the encoder, the FLEX.TM. paging protocol organizes the page, which includes the caller's message, into frames of data or a specific sized packet containing bits of data. There are a total of 128 frames in a FLEX.TM. protocol system, numbered zero through 127. It takes four minutes to transmit all 128 frames regardless of the FLEXTM speed. The transmission of all 128 frames is called a FLEX.TM. cycle. Since one cycle has a duration of four minutes, 15 cycles may be transmitted in one hour.
The paging signaling protocol is sent to the RF link system via telephone line, RF link or satellite. The RF link system includes the link transmitter and link receiver. The link transmitter sends the page to the link receiver, which is located at various paging transmitter sites along the channel. The paging transmitter translates the paging data into signals and broadcasts the message, or page, across the coverage area on the paging frequency or channel.
The final key component of a basic paging system is the messaging unit or pager. The pager receives the page from the paging transmitter. Each pager has incorporated in it a decoder unit. The decoder is able to recognize the unique code assigned to the pager and rejects all other codes for selective alerting. Pagers can be leased from a paging service provider or purchased through various retailers.
A cellular service is another type of communication service that is related to the present invention. The key components of a cellular system are cell base stations and cellular phones. Each cell base station consists of a transmitter/receiver, controller, and ideally, an omni-directional antenna resulting in a more or less circular radiation pattern. Each cellular phone consists of a low power transmitter/receiver, antenna and a microprocessor control unit.
The microprocessor control unit, within the cellular phone, samples the available communication channels until it finds one with the best reception. If the base station's strength diminishes during a call, the microprocessor control unit switches, or tunes, the cellular phone to another channel and the transmission is picked up from there. This automatic channel selection is called "handoff," and is normally inaudible to the caller, although it can be deadly to data transmissions.
Each call to a cellular phone is validated through the use of two numbers. Each cellular phone is personalized with an Electronic Serial Number (ESN) specific to the phone, and a Mobile Identification Number (MIN), otherwise known as the cellular phone number. Each call is validated at the base station cell by matching the ESN and the MIN.
A personal communication service (PCS) is another type of communication service that is related to the present invention. PCS is a broad term describing a number of systems and services which enable a caller to communicate anytime, anywhere, and in any form. The basic idea is based on the notion of allocating a single ID called a Universal Personal Telecommunication (UPT) number to a device allowing voice and data communication of any kind, anytime, and anywhere in the world. It is analogous to a Social Security number for communication.
PCS is a very recent byproduct of new digital communication techniques, whose roots are in covert military communications with high immunity to enemy jamming. Because PCS is digital in nature, it can easily handle data, messaging, paging, and in the future, full multimedia access with one device and one UPT.
Communication services need to offer much more than the basic systems described above to remain competitive. For instance, the paging system incorporates useful features into modern pagers such as a variety of alerting methods (e.g. using vibration, flashing lights and different beep tones) and the ability to send alphanumeric messages. Other useful features include group call, duplicate message detection, unread message counter, and message protection that prevents selected messages from being overwritten by incoming messages or erased by mistake.
Today's communication technology does not provide a means for the caller to confirm that a one-way communication message, such as a page, was received by the messaging unit. As mentioned above with cellular services, the automatic channel selection called "handoff" can be deadly to data transmissions. Therefore, the caller has no way of knowing if his message, or page, reached the desired destination. What is needed is a system and methodology for confirming the receipt of a message by a messaging unit, such as a pager.